They will be replaced by more "family-friendly" content aimed at older children and their parents, as well as a daily 20-minute CBeebies radio show online.

In another change, the BBC will make some of its children's radio archive available for broadcast by commercial rivals such as digital children's station, Fun Kids.

This means the total amount of children's programming broadcast on Radio 7/4 Extra will be cut from 1,400 hours to 350 hours a year.

The BBC Trust, which approved the changes, said the corporation had "struggled to serve children though its dedicated radio programming".

Children's programmes on Radio 7 were "performing very poorly ... and [that] hampers the overall performance of the station", the trust added.

The trust said the total number of listeners to Radio 7's morning CBeebies slot, which airs between 6am and 8am, was 125,000, of whom just 12,000 were aged between 4 and 14. Big Toe Books' listenership of 136,000 was slightly bigger, but only 21,000 were children.

"In fact, more children listen to other parts of the Radio 7 schedule," added the BBC Trust. "The average age of audiences to this children's programming is 48. This significantly limits the contribution that Radio 7 can make to this purpose through its dedicated children's content."

"Although there will be a reduction in hours of children's programming on Radio 7, we believe that BBC management's proposals for family-friendly content have the potential to improve the provision of speech radio for older children," the trust said.

The trust said the BBC should "explore opportunities to make children's radio archive available to commercial third parties to breathe new life into content that may not otherwise get future airings. This initiative should be treated as a priority".

Separately, the BBC Trust acted to safeguard the most popular elements of Radio 7 before it is rebranded Radio 4 Extra, upping the amount of comedy and drama it must broadcast each week, and capping the amount of Radio 4 catchup programmes at no more than 15% of its output throughout the year.

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